The developments in the field of snowboarding since its inception in the late Eighties, have resulted in the production of boards adapted for a diverse range of snow conditions and environments. The inherent suitability of snowboards for jumps, spins and the whole host of other tricks and aerial manoeuvres has led ski field operators to incorporate man-made terrain features such as kickers, table tops, quarter and half pipes (a combination of such elements often referred to generically as a ‘terrain park’) to facilitate such manoeuvres/tricks.
A half pipe is a particularly advantageous feature for a ski field as it enables a suitably proficient rider to execute multiple manoeuvres in a relatively short distance and ideally provides a well-defined, consistent take-off and landing areas, i.e. the walls of the half pipe. The disadvantage for a ski field operator is that a half pipe can be very labour-intensive to construct and difficult to maintain in optimum condition. As is well known to those skilled in the art and as may be deduced from the name, a half pipe consists of an elongated trench sloping down a snow covered mountain with symmetrical concave curved side walls extending along each longitudinal edge of the pipe.
Riders typically proceed down the pipe by alternately traversing between and riding up the two side walls, endeavouring to launch from the lip of the side wall to perform some form of aerial manoeuvre before landing back down the face of the side wall and traversing across to the opposing side of the pipe. An ideally shaped half pipe wall is thus formed as a smooth continuous concave curve, extending from the pipe floor and terminating in a substantially vertical top wall section. Producing and maintaining such half pipe walls with the desired curvature is extremely difficult and laborious to achieve manually. Known automated grooming methods employ a specific half pipe groomer attachment located on the front or rear of a conventional snow grooming vehicle. Whilst such attachments can provide a half pipe exhibiting the aforesaid desirable characteristics, the half pipe groomer attachments themselves suffer from several drawbacks, namely:                i. The attachment can be extremely cumbersome, with attendant drawbacks in terms of storage, maneuverability and undesirable stress on the grooming vehicle.                    As snowboarding is a relatively recent sport, the garage/storage areas most conventional snow grooming vehicle are not configured to easily accommodate existing half pipe groomer attachments. This may result in either the need for new purpose-built storage facilities or the need to store the attachment separately from the vehicle.                        ii. The attachment can often only be deployed and used on one side of vehicle. Thus, it is necessary to turn the vehicle around to groom both half pipe walls.        iii. The degree of curvature of the attachment cannot normally be altered.        
It will be appreciated that the shaping/grooming provided by the half pipe attachment may also be employed to enhance jumps and other terrain features, and in such instances the desired degree of curvature may differ from that used for a half pipe side wall. In some instances, the desired shape of the groomed surface may be straight or concave, or some combination of shapes. It would therefore be desirable to be able to shape such a surface with a single attachment, in a single pass. When mowing undulating or inclined surfaces such as roadside cuttings or embankments, it would be equally desirable to be able to follow the exact contours of the surface to give a uniform cut.